There is no such thing as a writer who has escaped being influenced. I have never heard a professional writer of any quality or standing talk about "pure" style, or say he would not read this or that for fear of corrupting or affecting his own; but I have heard it from would-be writers and amateurs. Corruption--if that is the word--sets in from the moment a child learns to speak and hear language used and misused. A young person who does not read, and read widely, will never write anything--at least, nothing of interest. From time to time, in France, a novel is published purporting to come from a shepherd whose only influence has been the baaing of lambs on some God-forsaken slope of the Pyrenees. His artless and untampered-with mode of expression arouses the hope that there will be many more like him, but as a rule he is never heard from again. For "influences" I would be inclined to substitute "acquisitions." What they consist of, and amount to, are affected by taste and environment, preferences and upbringing (even, and sometimes particularly, where the latter has been rejected), and instinctive selection. The beginning writer has to choose, tear to pieces, spit out, chew up, and assimilate as naturally as a young animal--as naturally and ruthlessly. Style cannot be copied, except by the untalented. It is, finally, the distillation of a lifetime of reading and listening, of selection, and rejection. But if it is not a true voice, it is nothing.
From Mavis Gallant, "What is Style?" in The Paris Notebooks (1986).